I don't know if you can dim CF bulbs. But we have fluorescent lighting that can be dimmed, at the university I teach at. How that is accomplished, I have no idea, but it works with no flicker.
I've heard that there are CF bulbs that are dimmable, but it is still an immature technology I think. It'll probably get better as time goes on.
Like somebody else commented upthread said... something to watch is the development of LED's. They're going to take over someday, I think. Bright, clean light, and a fraction of even CF power usage. They're not quite there yet, but I think they will be.
Both the ballast and the switch has to be capable of dimming.